I'd advise one of the three in and around Ratchaburi. Namely, Royal Ratchaburi, Dragon Hills or Panarangsi.
The first two are excellent courses and always in great condition. If I were to prefer one, it would be RR only because it's slightly easier IMO. There's absolutely nothing wrong with DH, but if you're not swinging well, it can be tough. Panarangsi is on an army base but it's OK to play there. A good test of golf with some awesome holes. The only thing that lets it down sometimes is the state of the greens. The first two are equal in condition to almost anything we get in and around HH. The clubhouses may not be as grand but you can get a shower, decent food and a cold beer.
And all of them are under 1,000 THB for green fee and caddie (midweek). Try and play in the morning and away from a weekend. The courses can get busy with local, Bangkok and Korean golfers in the afternoons, weekends and holidays.
One other thing, Panarangsi has a very good value pro shop for clothes and equipment. I've often detoured there when playing RR just to pop in and look around.
RR and Pangarangsi are quite close together on the northern outskirts of Ratchaburi town. DH is maybe 20 km south of the city.

Near Kanchanaburi, you can try Blue Sapphire or Evergreen. Both good courses - at least a few years ago the last time I was there. For something really different, try the Srinagarind course in the Erawan National Park - absolutely spectacular views and a tough course, publicly owned so very reasonably priced. If you're in Kanchanaburi Town, go to the One More Bar and ask for Rob, the owner. Good bar, great guy and knows just about all there is to know about the golf scene in Kanchanburi.